Smoke detector



June 30, v1942. c. c. sHEPPARD IN VEN TOR.

MORA/Ey June 30, 1942 C. c. SHEFFARDl 2,288,143

SMOKE DETECTOR Filed March 2o, 1941 s sheets-sheet 4/1 EJE- 4/ IN VENTOR. @maAZY e, glyyma,

BY` l Arm/MFV Patented June 3o, 1942 l UNITED STATES PATENT OFFICE sMoxEDETECTOR Creedy C. Sheppard, New York, N. Y. Application March 2o, 1941,serial no. 384,417 v 9 claims. (ci. sii-14) an apparatus of thischaracter wherein a source of light is provided at one side of the smokepassage and observation means at .the other side ythereof insubstantially the form of a periscope extending to a point at which thereman may easily look into the periscope while tending a fire anddetermine whether adjustments are necessary to eliminate excessive smokeowing through the smoke passage.

Another object of the invention is to provide a smoke detector whereinthe periscope portion thereof has mirrors mounted in an upper reiiectorbox, and a lower vision head or box, in a special manner to enable themto be readily adjusted while covers carrying the mirrors are closed. v

Another object Aof the invention is to provide the boxes with coverscarrying the mirrors and so mounted that they may be released and movedto open positions, in which positions the mirrors may be easily cleanedwhen necessary.

Another object of the invention is to provide the upper reflector boxwith a soot glass or shield serving as a transparent guard which willexclude smoke from this box and, to a large extent, prevent soot fromentering the upper end of the periscope and gathering upon the mirrors.

Another object of the invention is to so mount the soot glass that whenthe cover of the ector box is moved to open position, the soot glasswill move to a position in which it may be easily cleaned or removedfrom its carrier for thorough cleaning or repairs and then replaced, oranother soot glass substituted.

A further object of the invention is to provide the lower vision head orbox with a special form of vision glass having a clear portionsurrounded by a frosted or other translucent portion, the clear portionof the vision glass being used for observing heavy smoke and thetranslucent portion being used when observing light smoke. AIt will thusbe seen that when observing light smoke, the fireman or other attendantlooking through the vision glass or lens will not be blinded by theglare of a bright light and that a light of sufilcient intensity to beseen through heavy smoke when looking through the clear portion of thevision glass, may be employed.

Another object of the invention is to provide an apparatus of thischaracter which is simple in construction, easy to install, and veryefficient. in operation.

The invention is illustrated in the accompanying drawings, wherein: 1

Fig; 1 is a vertical sectional view showing the improved smoke `detectoroperatively associated with a pipe or equivalentsmoke passage.

Fig. 2 is a sectional view on an enlarged scale, showing the periscopewith the covers of the re- Y flector box and vision head closed.

Fig. 3 is a view showing the'lower vision head or box in frontelevation. l

Fig. 4 is a view similar to Fig. 2, showing the covers of the reectorbox and vision head or box open.

Fig. 5 is a view in elevation, of the smoke lglass and its carrier.

Fig. 6 is a view showing the smoke glass carrier mounted on the cover o!the reflector box, the rtzover being In section and the carrier inelevaion.

Fig. 7 is aview looking at the outer face of the glass of the visionbox.

Fig. 8 is a side view of the Fig. 7.

The improved smoke detector constituting the subject matter of thisinvention is to be mounted in cooperating relation to a smoke passage I,which may be a stove pipe, chimney flue, or the glass shown in like, andconsists briefly of a source of light 2` and a periscope 3 having atubular body 4 of desired length and diameter `and threaded at its endsfor engagement with an upper reflector box 5 and a lower vision head orbox 6. Mirrors 'l and 8 are mounted in the boxes 5 and 6, and by lookinginto the vision box 6 through the glass 9, a fireman, or other person incharge of a furnace, may observe a reflection of the products ofcombustion passing through the smoke passage and determine whether toomuch smoke is being given oi by the furncae.

The cource of light consists of a bulb I0. carried by a socket II whichis mounted in a casing I2 provided with a lens I3 at its front end. Acoupling I4 of box-like formation ,connects the casing I2 with a tube orpipe I5 having one end mounted through an opening I5 at one side of theflue or smoke passage I, so that when the smoke-detector is inoperation, light from the the bolt is loosened and swung out of theslotted ear, the section may be swung away from the section I1 to openposition, and access had to its interior for inserting the light bulb orcleaning the lens i3. A ring 22 holds the collar 23 at the front end ofthe lamp casing I2 against the ange 24 of the coupler section I5, itbeing understood that other means for removably holding the lamp inplace may be employed, if de-` sired.

'I'he periscope 3 is mounted at the opposite side of the smoke passageor ilue I and its upper reilector box 5 is formed with a threaded neck25 to receive the threaded outer end of a tube or pipe 25 which'has itsinner end mounted through an opening 21 formed in the ilue I indiametricalLv opposed relation to the opening I5. Therefore, the tubesI5 and 26 will be in alinement and light from the bulb may pass throughthe tube 25 and into the upper reiiector box. The upper and lower boxes5 and 5 are of substantially duplicate construction and each has a neck25, ends of the tubular body 4 being screwed into these necks.- The dooror cover 29 of each box is cupshaped and formed with anoutstandingiiange 3l carrying a hinge ear 3|. the ear of one cover beingpivoted to the neck 25 ofthe upper box and the ear of the other coverbeing pivoted to the neck 28 of the lower box so that the covers may beswung from the *closed position of Fig. 2 to the open position of Fig.4. A clamp 32 is employed to hold each cover closed and consists of apivoted bolt 33 which is passed through a slot 34 of the flange andtightened to securely but releasably hold the cover closed.

The covers are of cup-shaped formation in order to receive the mirrors 1and 5, each of which is mounted in a frame or carrier 35 which is ofconcavo-convex formation, the mirror being held in the frame by aretainer 30. A stem 31 which is secured `to the carrier, centrallythereof, by nuts 38, extends rearwardly from the carrier 35 through thebore 39 of a neck 43 projecting outwardly from the cover 25 andterminates in a ball or spherical head 4I. The head 4I rests in a seat42 at the outer end of the bore 39 and when the cap 43 is tightened,frictional binding will prevent movement of the ball in its seat.Therefore, the mirror may be held in angularly adjusted position andaperson looking into the visionbox 3 through the glass 9, may see areiiection of smoke passing upwardly through the flue I. When the bolt33 is loosened and the cover swung to open position. the. mirror may bereadily cleaned. Each of the balls 4I is formed with a sock 4I' leadingfrom its exposed outer portion to receive an adjusting rod R which isthrust into place when adjustment is necessary.'as indicated by dottedlines in Fig. 2. Therefore, the mirrors may be tilted to adjustedposition when the covers are closed and an accurate adjustment easilyaccomplished.

In addition to carrying the mirror 1, the cover of the reflector box 5also carries a soot glass 44. This glass is clear and is provided with aframe 45 having a circumferentially extending groove 45 to receive theopen ring 41 of a carrier 43.

. manner which will prevent a This carrier is formed of resilient wireand has its end portions bent to form arms 49 which are further bent toform fingers 50 terminating in eyes 5I through which bolts 52 pass tosecure the carrier to theinner surface oi the cover. When the cover isclosed, the soot glass iirst engages the inner end of the neck 25 of thereector box and as the cover is fully closed and secured by the clamp32, the resilient carrier will be tensioned to firmly hold the sootglass in covering relation to the inner end of the neck 25. It will thusbe seen that soot which may enter the neck will be excluded from thereector box 5 and dimming of the mirrors bysoot accumulated thereon willbe eliminated. When the soot glass becomes clouded, the cover of thereflector box is released and swung to its open position, when the sootglasswillthenbedisposedasshowninFig.4of the drawings and may'be easilycleaned.

The vision glass 5 is of special formation. 'I'his glass is illustratedin Figs. 7 and 8, and shown in position in Figs. l, 2, and 4 of thedrawings. Referring to these ilgures. it will be seen that the visionglass is of concavo-convex formation and is held in place in closingrelation to the front `.opening 53 of the vision box 6 by a ring 54which overlaps margins of the glass and is secured to the' wall of thebox by screws 55. The central portion 55 of the glass 9 is clear andsurrounding by a circumferentially extending band 51 which is preferablyfrosted but may be treated in any persons sight being interfered with byglare when looking through this portion of the glass. When thick smokeis passing through the ilue passage. the fireman or other person havingcharge of the furnace, looks through the clear central Klass 9 and agood view of the tained. as glare from the dimmed by the smoke. Whenlight smoke is passing through the ilue, the light from the lamp will beonly slightly dimmed, if at all, and a person looking through the clearportion of the smoke may be oblight rays will be sight glass would beblinded by the glare, the

same as ifhe were looking Under these conditions, through the frostedportion glare from the light rays be able to see the soot frosted.portion of the heavy or dark ysmoke is as the light will be smoke sothat he directly at the bulb I3. the attendant looks oi' the glass andsince will be dimmed, he will in the light smoke. The glass is not usedwhen passing through the iiue, dimmed sufliciently by the can readilysee the soot in the smoke. It will be obvious thatadditional bends couldbe provided in the periscope and boxes carrying mirrors provided at eachbend. It will also be understood that the periscope may extendvertically or at any other angle desired and that the boxes may beangularly adjusted to suit the convenience of the person having chargeof the furnace.

Having thus described the invention, what is claimed is: Y Y

1. In a smoke detectora light source mount-v ed at one side of a smokestack, a reilector box at the opposite side of and an outlet at rightangles to each other and an opening between the same, a hinged cover forlthe opening of the, reflector box, a reflecting mirror carried by saidcover inwardly thereof and disposed within the box diagonally of theinlet and the outlet when the cover is closed. a sootglass and amounting for the soot-glass carried by. the cover and mounting thesoot-,glass inwardly of the reilector in position for ciodng portion ofthe sight the stack having an inlet relation to the inlet when the coveris closed, the mountingI for the soot glass being resilient toyieldablymount the soot-glass and permit yielding oi the mounting andaccurate seating of the soot-glass in closing relation to the inletduring closing of the cover.

2. In an observation device of the character described, a box formedwith an inlet and an outlet, a cover for the box hingedly mountedopposite the inlet for movement into and out of a closed position, amirror, a holder for the mirror 3. vIn a smoke detector, a box formedwith an inlet and an outlet, a cover hingedly mounted opposite the inletfor movement into and out of ly mounted for movement into and out ofclosed position, a mirror carried bythe cover and disposed diagonally ofthe inlet and the outlet within the box when the cover is closed, atransparent shield for closing'the inlet, and a carrier for the shieldformed of resilient wire and having aportion tting about the peripheryof the shield and arms extendingr therefrom, the arms being securedagainst the inner surface of the-cover and yieldably mountingr theAshield lor accurate seating in blocking relation to the inlet when thecover is closed.

7. In an observation device of the character described, a box. formedwith an inlet and an outlet at right angles to the inlet, the box beingclosed position, a mirror, a holder for the mirror adjustably connectedwith the cover and mountingwtlie'mirror for angular adjustment, a sootglass [or closing the inlet having a frame, and a carrier for the sootglass engaged with the frame and secured to said cover, said carriermounting the soot glass for movement with the cover into and out ofclosing relation to the inlet and be ing formed of resilient material topermit yieldmovement and accurate seating of the soot glass in shieldingrelation to the inlet duringclosing of the cover.

4. In a smoke detector, a bcx formed with an inlet and an outlet, acover hingedly mounted opposite the inlet for movement into and out ofclosed position, a mirror, a holder for said mirror adjustably connectedwith the cover and mounting the mirror for angular movement, a sootglass for closing the inlet having a frame, and a carrier for the sootglass formed of resilient wire and having a ring like portion ttingabout the frame and arms extending therefrom, the arms being securedagainst the inner surface. of the cover and yieldably mounting the sootglass for accurate seating in blocking relation to the inlet when thecover is closed.

also formed with a diagonally extending opening opposite the inlet, acover hingedly mounted for movement into and out of closing relation tothe diagonal opening, a mirror, a holder for the mirror adjustablyconnected with the cover and mounting the mirror within the box forangular 5. In an observation device of the character described, ahousing formed with an inlet and an outlet located transversely of. theinlet, an opening being formed in the housing between the inlet and theoutlet and located opposite the inlet, a cover for the opening mountedfor movement into and out of closed position, a mirror formed ofresilient material to permit yielding movement and accurate seating ofthe shield adjustment relative to the inlet and the outlet, a soot glassfor closing the inner end of the inlet having a frame, and a carrier forthe soot glass engaged with the frame and secured to the inner face ofsaid cover and mounting the soot glass in front of the mirror in spacedrelation thereto, said carrier mounting the soot glass for movement withthe cover through the box into `and out of closing relation to theinlet:I during opening and closing of the cover and being formed ofresilient material to yieldably mount the soot glass and permit accurateseating of the soot glass in closing relation to the inlet and completeclosing of the cover after the soot glass is seated.

8. In a periscope-type smoke detector, a vision head having aconcavo-convex vision glass projecting outwardly from the head with itsconvex surface presented outwardly, said glass havy ing a circularcentrally located clear portion for observation of heavy smoke against alight source and a translucent portion for observation of light smokeagainst the light source entirely surrounding the clear portionconcentric therewith between the periphery of the clear portion and themarginal edge of the vision glass, the translucent portion being of awidth appreoiably less than the diameter of the clear portion.

9. In a periscope-type smoke detector, a/vision head having aconcave-convex vision glass, the

convex surface of the vision glass being presented outwardly, the visionglass being non-magnifying and having a clear central portion concentricwith the glass and entirely surrounded by a translucent portionconcentric with the central portion and covering the entire area of theglass between the periphery of the central portion and the periphery ofthe glass.

CREEDY C. SHEPPARD.

